These Emperors wear no clothes.
The Emperor Penguin (Aptenodytes forsteri) is the largest of all penguin species, and can be found in Antarctica. They are true natives of the Antarctic, rarely venturing into sub-Antarctic waters and mating during the harsh winters of the South Pole. This is the coldest breeding environment for any bird species in the world, and the Emperor Penguin has adapted to survive. They are covered in a dense layer of feathers, with 15 feathers per square centimeter. Under that, they have a layer of down that helps to provide insulation. And beneath their skin, a thick layer of blubber that makes for awkward mobility on land, but helps keep them warm. Preening is essential in maintaining the outer seal of feathers, however, which provides most of their insulation.
Adult Emperor Penguins tower over other penguin species, standing up to 51 inches (130 cm) tall. Weight varies by sex and by season, ranging from 50 to 100 pounds (22.7 to 45.4 kg). Right before the breeding season, the layer of blubber that protects them from the cold can be up to 1.2 inches (3 cm) thick. Emperor Penguins are built to keep their body heat in, being able to thermoregulate without changing their metabolism. They have distinctive yellow markings around their throats and upper breast, and chicks are born with fuzzy gray down.
The diet of Emperor Penguins consists of fish, cephalopods, and crustaceans. They have barbs on their tongues and the insides of their mouths to prevent fish from wiggling free after being grabbed. One strategy that they use to hunt fish is to dive down to depths of 164 feet (50 meters) so that it can spot fish silhouetted against the bright surface or bottom of sea ice, then zoom up to catch the fish. It can do this about six times before ever needing to return for the surface to breathe, and they can dive even deeper when necessary. The Emperor Penguins’ heart rates slow when they dive deep, to reduce oxygen consumption. The hemoglobin and myoglobin in their blood stream is able to transport oxygen at low blood concentrations, allowing the Emperor Penguin to function at an oxygen level that would cause many other animals to pass out.
In March and April, the Antarctic winter is just getting started, and the sexually mature Emperor Penguins congregate in the breeding colonies to find their mates. They form breeding pairs very quickly, because when it’s -60 degrees Celsius, no one has time to be really picky. Emperor Penguins do not mate for life, but they are serially monogamous, mating with only one other penguin each season. Males engage in a courtship display and make mating calls, waiting for a female to respond. Emperor Penguin vocalizations are extremely important in communication, with each penguin developing a unique call so that they can recognize each other. The females lay one egg and immediately transfers it to the male’s brood pouch, before it freezes. Egg production takes up a lot of resources, so the females must head back to sea in order to feed, or they would not survive. The males incubate the eggs during this time period, about 64 days. To survive, the males huddle together for warmth, and by the time their eggs hatch and the females have returned, they will have fasted for approximately 115 days.
In 2012, Emperor Penguins were uplisted by the IUCN from a species of least concerned to near threatened, because the species is projected to endure a rapid and significant population decline in the near future. It is currently being considered for inclusion in the U.S. Endangered Species List because of the impact that commercial fisheries have on its food supply, as well as the effect that climate change can have on the sea ice that is crucial for its survival. Emperor Penguins are very social birds, staying together for both nesting and foraging.
Source for all images used in this post.